LONDON  Environmentalists hung 113,000 feet (34,400 meters) of laundry out to dry in Trafalgar Square on Monday, part of a multi-agency effort on U.N. World Environment Day to protest British reliance on energy-sapping dryers.

"You're looking at the biggest one-line joke in history," the project's supervisor and British comedian Tim FitzHigham said to the assembled crowd.

The all-day demonstration used 4,920 items of washing and 24,600 clothespins.

"All around the world today, people are drawing attention to the environment and the damage we've done to it," comedian and actor Alistair McGowan said. "But it's not just a day where you've got to do something for the environment -- it's the next day, and the next, and on."

The decision to focus on air-drying laundry was Britain's particular stamp on the international event -- the "main force of our argument," McGowan said.

The Environment Agency said that if each family in Britain hung up just one load of washing each week, that would save 88 million pounds (euro128 million; US$166 million) and prevent over 500,000 tons of carbon dioxide emissions per year.

"This is a great visual way to show people what a difference we can make," EA spokesman and wash-hanging volunteer Nick Rijke said. "Yes, we want the government to do more, but was also want people individually to do more -- more than simply wait for shifts in government policy."

Materials used to create the clothesline -- from the wash to the metal poles to the clothespins -- would of course be recycled, FitzHigham said.

"At the end of the day, it's my hope that Britain will be proud to have aired more dirty laundry in public than any other nation on the planet," he said.